Dimerization of olefins with boron trifluoride

ABSTRACT

A process is provided for dimerizing 1-olefins which comprises contacting such olefins in a reaction zone with a minor proportion of at least one catalyst selected from the group consisting of phosphoric acid-promoted and water-promoted boron trifluoride catalyst in a mole ratio of catalyst to olefins of from about 0.005:1 to about 0.1:1 and at a temperature from about 100*C. to about 150*C.

United States Patent 11 1 Brennan 1 DIMERIZATION 0F OLEFINS WITH BORON TRIFLUORIDE [75] inventor: James A. Brennan, Cherry Hill, NJ.

[73] Assignee: Mobil Oil Corporation, New York,

22 Filed: Nov. 18, 1971 21 Appl. No.: 200,237

[52] U.S. Cl. 260/683.9, 260/683.15 B

[51] Int. Cl C07c 3/18 [58] Field of Search 260/683.14 B, 683.15 C, 260/683.9

[56] References Cited UNITED STATES PATENTS 3,149,178 9/1964 Hamilton et a1. 260/683.9

3,576,898 4/1971 Blake et a1 260/676 2,148,116 2/1939 Gerhart et a1. 260/683.15

2,183,503 12/1939 McAlevy 260/683.15

[ June 26, 1973 2,766,312 10/1956 Serniuk 260/683.l5 2,810,774 10/1957 Semiuk 260/683.15 2,816,944 12/1957 Muessig et a1. 260/683.15 2,976,338 3/1961 Thomas 260/683.15 3,214,486 10/1965 Doyle et a1. 260/676 2,552,508 5/1951 Peters 260/683.15

Pri y, xqm aerf w qus e Attorney-Andrew L. Gaboriault, Oswald G. Hayes, Benjamin 1. Kaufman et a1.

ABSTRACT 5 Claims, No Drawings DIMERIZATION OF OLEFINS WITH BORON TRIFLUORIDE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the dimerization of olefins and relates more particularly to a controlled process for dimerizing l-olefins with boron trifluoride catalysts. Still more particularly, in one of its aspects, the invention relates to an improved process for the manufacture of l-olefin synthetic wide-temperature fluid lubricants by dimerization of olefin fractions employing phosphoric acid-promoted or water-promoted boron trifluoride catalysts, or mixtures of such catalysts, under controlled conditions to obtain preponderately olefin dimers suitable for use as synthetic wide-temperature fluid lubricants for many industrial applications.

2. Description of the Prior Art As is known to those skilled in the art, boron trifluoride, per se, is a poor catalyst for polymerization of olefins, unless it is employed in conjunction with a suitable promoter. For this purpose, the prior art has suggested among other materials the use of phosphoric acidpromoted or water-promoted boron trifluoride. In this respect, such polymerization techniques have heretofore been conducted at relatively low temperatures, for example, below about 60C., and usually from about C. to about 35C. However, reaction at these temperatures yields products unsuitable for this application. Polymerization of long-chain olefins at higher temperatures such as 100C. is generally accompanied by undesirable reactions such as isomerization or cracking.

SUMMARY OF THE INVENTION In accordance with the present invention, it has now been found that the dimerization of l-olefins can be carried out without cracking and in increased product yield by employing relatively high dimerization temperatures and conducting the dimerization in the presence of phosphoric acid-promoted or water-promoted boron trifluoride catalysts, or mixtures thereof, under controlled conditions. More specifically, as hereinafter described, an improved process is provided for dimerizing l-olefins by contacting such olefins in a reaction zone with a minor proportion of at least one catalyst selected from the group consisting of phosphoric acid-promoted and water-promoted boron trifluoride catalysts in a mole ratio of catalyst to olefins of from about 0.00521 to about 01:1 and at a temperature from about 100C. to about 150C., and preferably at a temperature from about 100C. to about 125C.

In conducting the dimerization, in order to obtain relatively high yields of dimerizate product while minimizing concomitant cracking or decomposition, it is essential that the mole ratio of catalyst to olefin be maintained in the aforementioned mole ratio of from about 0005:! to about 0.1:1. When phosphoric acidpromoted boron tribluoride catalyst are employed, the preferred mole ratio of catalyst to olefin is about 0.00521; when water-promoted boron trifluoride catalysts are employed, the preferred mole ratio of catalyst to olefin is about 0.01:1. The phosphoric acid boron trifluoride promoter may be prepared in several ways. For example, this promoter may be prepared by reacting 85 percent phosphoric acid and boron trifluoride at a temperature below about 50C. with the boron trifluoride being introduced into the acid in the form of a gas. In

preferred applications, this promoter contains boron trifluoride and phosphoric acid in equimolar proportions. The water boron trifluoride promoter may be prepared by simply complexing boron trifluoride in a mole ratio of about 1:1 with water. An essential feature of the process of the present invention resides in the technique of carrying out the dimerization at relatively high temperatures, low promoter concentrations, and quenching the reactionjust prior to the time that crack ing or decomposition can occur in order to obtain maximum yields. Conversely it is found that if dimerization temperatures below about 100C. are employed, the degree of oligomerization is too high, resulting in a relatively high molecular weight dimer product which is too viscous for use in such applications as, for example, hydraulic fluids. Particularly desirable for many industrial applications are dimerization products of l-olefins containing from about six to about 10 carbon atoms. In more specific applications, it is found, in accordance with the present invention, that dimers, for example, dimers of l-decene prepared by dimerization carried out in the presence of the aforementioned phosphoric acidpromoted or water-promoted boron trifluoride catalysts, under the above-described conditions, possess muchlower pour points than the polymerization products of the same olefins, prepared by polymerization processes employing conventional ditertiarybutyl peroxide catalysts or Ziegler catalysts, because the products obtained throughthe use of the latter catalysts contain relatively large amounts of high melting n-eicosane, whereas the promoted boron trifluoride products of the present invention contain none.

DESCRIPTION OF SPECIFIC EMBODIMENTS The following examples will serve to illustrate the novel process of the present invention for conducting the dimerization of l-olefins to yield products of improved quality.

A series of water and phosphoric acid-promoted boron trifluoride catalyzed oligomerizations of ldecene was carried out. The individual catalysts were preformed from either water or percent phosphoric acid by bubbling boron trifluoride through until one molar equivalent of the halide was absorbed. l-decene was next introduced through the bottom of a water trap saturated with boron trifluoride and allowed to overflow into a reaction flask. The individual oligomerizations were carried out in the following manner.

The boron trifluoride saturated l-decene and the water-boron trifluoride molar adduct were metered, by means of syringe pumps separately and simultaneously into the reaction flask. The flask was previously pressured with boron trifluoride to 2 inches of mercury and maintained at C. The pump rates were 2.38 g/min. and 0.016 g/min. for decene and and promoter, respec tively. The addition was completed in 63 minutes. The resulting mixture was then stirred for 15 minutes at 100C., quenched with 100 ml of 10 percent ammonium hydroxide, water-washed until neutral and finally filtered. The resulting mixture was then analyzed by gas chromatography, as shown in the following Table I. The monomer was next removed by distillation at 50 mm pressure employing a l2-inch Vigreaux column and at-a take-off rate of one drop per second. The head temperature during monomer removal varied from 80 to C. Topping of 134.9 g. of the resulting mixture yielded 117.2 g. of dimer plus product. The recovered TABLE I thereof may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand.

I claim:

1. A process for climerizing l-olefins having from about six to about carbon atoms, which comprises contacting said olefins in a reaction zone with a minor Water or Phosphoric Acid lromututl Boron Trilluurirlu Catalyzed ()ligomerizatimis oi l-lh't-rnv Moles h'lllltfilvily, purcnnl pimnotur 'limu mv., V

100 u. -Y----- W 'il'llllh, wt. 'lvLmnu-r Example l'rmnulur (locum: Add 110111 1. llll't'ttlll. Uimvr 'lrimvr plus 1 1120411 11 0.00s 3 15 up an 75.7 ms 5.1 2 H rm-15F; 0.0036 51 til, 120 m3 73.3 211.6 0.1

TABLE ll proportion of at least one catalyst selected from the Kinematic viscosity, cuntistokes group consisting of phosphoric acid-promoted and waplus some 0 100:: F. Q F F. ter-promoted boron triflouride catalysts in a mole ratio 1 94 6 45 m 1 730 of catalyst to olefins of from about 0.005zl to about 2101 7:06 535 21407 0. l :1 and at a temperature from about 100C. to about 1) 1. 09 6.73 451 2.112 e Example2alter hydrogenation. 2.07 7. 26 150 C." removlng free motion}?! from the dlmenzed olefinic product, and SllbjBCtll'lg the monomer-free product thus obtained to hydrogenation.

It will be apparent from the foregoing Tables 1 and 11, that the dimerization of olefins employing phosphoric acid-promoted or water-promoted boron trifluoride catalysts, within a mole ratio of catalyst to olefin from about 0.005:l to about 0. l :1 and at temperatures from ,about 100C. to about 150C, results in obtaining rela- 2. A process in accordance with claim 1 wherein said dimerization is carried out with a phosphoric acidpromoted boron trifluoride catalyst in a mole ratio of catalyst to olefins of from about 0.005z1.

3. A process in accordance with claim 1 wherein said dimerization is carried out with a water-promoted boron trifluoride catalyst in a mole ratio of catalyst to olefin of about 0.01:1.

4. A process in accordance with claim 1 wherein said dimerization is carried out at a temperature from about C. to about C.

5. A process in accordance with claim 1 wherein said l-olefins comprise l-decene.

STATES PATENT OFFECE CERTIFICATE OF CORRECTION p N 3,7LL2,O82 mud June 26, 1973 Invgntgr(.) JAMES A. BRENNAN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F Column 1, line 58, "tribluoride should read "trifluoride-n Column 1, line 58, "catalyst" should read "catalysts".

Table II, under heading '65F.', 1.730", "2A07, "2.112 should read --l730--, --2 LO7--, --2ll2 Signed and sealed; this 26th day of, Februar 19m.

(SEAL) Attest: V

EDWARD M.FLETCHEIR,JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

2. A process in accordance with claim 1 wherein said dimerization is carried out with a phosphoric acid-promoted boron trifluoride catalyst in a mole ratio of catalyst to olefins of from about 0.005:1.
 3. A process in accordance with claim 1 wherein said dimerization is carried out with a water-promoted boron trifluoride catalyst in a mole ratio of catalyst to olefin of about 0.01:1.
 4. A process in accordance with claim 1 wherein said dimerization is carried out at a temperature from about 100*C. to about 125*C.
 5. A process in accordance with claim 1 wherein said 1-olefins comprise 1-decene. 